I am thinking about this particular form of proportional representation for a parliamentary system and I am wondering if it has been used before. This is how it works.
Half the seats in Parliament are filled by first past the post vote, similar to what is being used in the UK and the US.
Then, a list is made for the losers of each party by the order of how close they are to the winner of their districts.
Now, say a party got 40 seats in the first half of the Parliament but it should've gotten 80 seats based on popular vote across the country. Then, the party got 40 seats extra. However, these seats are not chosen by the party like the open list in Germany or the closed list in Venezuela but are taken from the first 40 names on the list of losers for each party.
So each party is proportionally represented.
The reason I like this method is that for example if a winner in a district gets 35% of the vote while the 2nd placer and 3rd placer got 33% and 20% of the vote, respectively. Then, there is a strong chance that one of the losers will get a seat, thus about 60% of the district's vote is represented.
The only disadvantage I can think of is that some districts will get more than one representative while others will get only one.
Has this form of election system been used before and what are the pros and cons of such a system?